scholarly journals The Properties of OPEFB Cellulose Nanofibrils Produced by A Different Mode of Ultrafine Grinding

2021 ◽  
Vol 891 (1) ◽  
pp. 012016
Author(s):  
P Amanda ◽  
S Nabila ◽  
N Qonita ◽  
R S Ningrum ◽  
Ismadi ◽  
...  
Keyword(s):  
Kraft Pulp ◽  
Cellulose Nanofibrils ◽  
Crystallinity Index ◽  
Morphological Properties ◽  
Mechanical Grinding ◽  
Bleached Pulp ◽  
Ultrafine Grinding ◽  
The Hierarchical Structure ◽  
Size Uniformity ◽  
Mechanical Fibrillation

Abstract Cellulose Nanofibrils (CNFs) was resulted from deconstruction of the hierarchical structure of cellulose. CNFs are commonly obtained by mechanical fibrillation, such as ultrafine grinding processes and its variation. Nevertheless, the influence of different treatments on the properties of the resulting CNF especially from variety of ultrafine grinding mode has not been reported. This study investigates the properties of cellulose nanofibrils (CNF) produced from bleached pulp oil palm empty fruit bunch (OPEFB) Kraft pulp through an ultrafine grinder with two different treatments in the fibrillation process. These two treatments were: 1) ultrafine grinder with increasing gaps distances; -30, -50, -70, and -90 µm with five cycles in every gap, 2) ultrafine grinder on constant gaps (-30µm) with increasing grinding cycles: 5, 10, 15, 30, and 40 cycles through the grinder. The influence of the treatment was evaluated through particle size distribution, crystallinity index, and morphological properties. The result showed that the increasing gaps treatment efficiently improved the size uniformity of CNFs, length 147-139.5 nm, and scanning electron microscope micrograph confirmed that the diameter of CNF was smaller with the increasing grinding gaps than increasing grinding cycles. However, the increasing cycle’s treatment produced CNF with a higher crystallinity index. The crystallinity index (CrI) of the CNF decreased from 71.27 to 62.25% with increasing gaps, whereas the CrI of the CNF from increasing cycles was 69.35%. This study provides a valuable guideline for determining the appropriate process to produce CNF especially by mechanical grinding using ultrafine grinder from OPEFB according to the desired result.

Effects of mechanical fibrillation time by disk grinding on the properties of cellulose nanofibrils

TAPPI Journal ◽  
2016 ◽  
Vol 15 (6) ◽  
pp. 419-423 ◽  
Author(s):  
QIANQIAN WANG ◽  
J.Y. ZHU
Keyword(s):  
Energy Input ◽  
Cellulose Nanofibrils ◽  
Crystallinity Index ◽  
Degree Of Polymerization ◽  
Optical Transparency ◽  
Structure And Properties ◽  
Eucalyptus Pulp ◽  
Mechanical Fibrillation ◽  
Cnf Films ◽  
Grinding Time

Cellulose nanofibrils (CNF) were successfully produced from a bleach kraft eucalyptus pulp by a supermasscolloider. Effects of grinding time on structure and properties of CNF and the corresponding CNF films were investigated. Grinding time was important to increase the optical transparency of CNF suspensions. The degree of polymerization (DP) and crystallinity index (CrI) of CNF decreased linearly with the increase in CNF suspension transparency. This suggests optical transparency of a CNF suspension can be used to characterize the degree of fibrillation. Specific tensile strength and Young’s modulus of the CNF films made of CNF suspension with only 0.5 h grinding were increased approximately 30% and 200%, respectively, compared with conventional handsheets prepared by valley beating to 300 Canadian Standard Freeness (CSF). Energy input was only 1.38 kWh/kg for 0.5 h grinding. Grinding beyond 0.5 h produced negligible improvement in specific tensile and specific modulus. Opacity of CNF films decreased rapidly during the first 1.5 h of fibrillation and then plateaued.

scholarly journals Synthesis of Nanofibrillated Cellulose by Combined Ammonium Persulphate Treatment with Ultrasound and Mechanical Processing

Nanomaterials ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 640 ◽  
Author(s):  
Inese Filipova ◽  
Velta Fridrihsone ◽  
Ugis Cabulis ◽  
Agris Berzins
Keyword(s):  
Zeta Potential ◽  
Mechanical Treatment ◽  
Kraft Pulp ◽  
Cellulose Nanofibrils ◽  
Crystallinity Index ◽  
Nanofibrillated Cellulose ◽  
Ammonium Persulfate ◽  
Pulp Fibers ◽  
Persulfate Oxidation ◽  
Birch Kraft Pulp

Ammonium persulfate has been known as an agent for obtaining nanocellulose in recent years, however most research has focused on producing cellulose nanocrystals. A lack of research about combined ammonium persulfate oxidation and common mechanical treatment in order to obtain cellulose nanofibrils has been identified. The objective of this research was to obtain and investigate carboxylated cellulose nanofibrils produced by ammonium persulfate oxidation combined with ultrasonic and mechanical treatment. Light microscopy, atomic force microscopy (AFM), powder X-Ray diffraction (PXRD), Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and Zeta potential measurements were applied during this research. The carboxylated cellulose suspension of different fractions including nanofibrils, microfibrils and bundles were produced from bleached birch Kraft pulp fibers using chemical pretreatment with ammonium persulfate solution and further defibrillation using consequent mechanical treatment in a high shear laboratory mixer and ultrasonication. The characteristics of the obtained nanofibrils were: diameter 20–300 nm, crystallinity index 74.3%, Zeta potential −26.9 ± 1.8 mV, clear FTIR peak at 1740 cm−1 indicating the C=O stretching vibrations, and lower thermostability in comparison to the Kraft pulp was observed. The proposed method can be used to produce cellulose nanofibrils with defined crystallinity.

Combined mechanical grinding and enzyme post-treatment leading to increased yield and size uniformity of cellulose nanofibrils

Cellulose ◽  
2020 ◽  
Vol 27 (13) ◽  
pp. 7447-7461 ◽  
Author(s):  
Caihong Zhang ◽  
Min Wu ◽  
Shuang Yang ◽  
Xueping Song ◽  
Ying Xu
Keyword(s):  
Cellulose Nanofibrils ◽  
Post Treatment ◽  
Mechanical Grinding ◽  
Size Uniformity

Facile preparation of nanofiller-paper using mixed office paper without deinking

TAPPI Journal ◽  
2015 ◽  
Vol 14 (3) ◽  
pp. 167-174 ◽  
Author(s):  
QIANQIAN WANG ◽  
J.Y. ZHU
Keyword(s):  
Cellulose Nanofibrils ◽  
Ash Content ◽  
Raw Material ◽  
Mechanical Grinding ◽  
Microscope Imaging ◽  
Facile Preparation ◽  
Electron Microscope Imaging ◽  
Thermal Stability Of ◽  
Scanning Electron ◽  
Office Paper

Mixed office paper (MOP) pulp without deinking with an ash content of 18.1 ± 1.5% was used as raw material to produce nanofiller-paper. The MOP pulp with filler was mechanically fibrillated using a laboratory stone grinder. Scanning electron microscope imaging revealed that the ground filler particles were wrapped by cellulose nanofibrils (CNFs), which substantially improved the incorporation of filler into the CNF matrix. Sheets made of this CNF matrix were densified due to improved bonding. Specific tensile strength and modulus of the nanofiller-paper with 60-min grinding reached 48.4 kN·m/kg and 8.1 MN·m/kg, respectively, approximately 250% and 200% of the respective values of the paper made of unground MOP pulp. Mechanical grinding duration did not affect the thermal stability of the nanofiller-paper.

An effective method for determining the retention and distribution of cellulose nanofibrils in paper handsheets by dye labeling

TAPPI Journal ◽  
2018 ◽  
Vol 17 (03) ◽  
pp. 157-164 ◽  
Author(s):  
Shengdan Wang ◽  
Wenhua Gao ◽  
Kefu Chen ◽  
Jinsong Zeng ◽  
Jun Xu ◽  
...  
Keyword(s):  
Correlation Coefficient ◽  
Congo Red ◽  
Kraft Pulp ◽  
Cellulose Nanofibrils ◽  
Standard Curve ◽  
Congo Red Dye ◽  
Mechanical Disintegration ◽  
Softwood Kraft Pulp ◽  
White Water ◽  
Red Dye

Cellulose nanofibrils (CNF) were prepared by cellulase in conjunction with mechanical disintegration from the bleached softwood kraft pulp and labelled by Congo red dye. The labelled CNF were used to investigate the retention and distribution of CNF in paper handsheets. The retention of the labelled CNF was obtained by measuring the absorbance of white water using an ultraviolet-visible spectrophotometer. The results showed that this method for measuring the retention was rapid, feasible, and sensitive, owing to the high correlation coefficient R2 (0.9993) of the standard curve. The labelled CNF showed even distribution in paper handsheets. The colorimetric values of paper handsheets were explored with a residual ink analyzer.

scholarly journals An Efficient Method for Cellulose Nanofibrils Length Shearing via Environmentally Friendly Mixed Cellulase Pretreatment

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Yuan Chen ◽  
Yuchan He ◽  
Dongbin Fan ◽  
Yanming Han ◽  
Gaiyun Li ◽  
...  
Keyword(s):  
Cellulose Nanofibrils ◽  
Trichoderma Viride ◽  
Cellulose Fibers ◽  
Effective Diameter ◽  
Layer By Layer ◽  
Mechanical Grinding ◽  
Hydrolysis Time ◽  
Sem Images ◽  
Enzymatic Pretreatment ◽  
Cellulase Hydrolysis

Cellulose nanofibrils (CNFs) have potential applications in the development of innovative materials and enhancement of conventional materials properties. This paper focused on the mixed cellulase hydrolysis with major activity of exoglucanase and endoglucanase on the cellulose length shearing. By the cooperation of two-step production route, including (1) enzymatic pretreatment using cellulase fromTrichoderma virideand (2) mechanical grinding twice, a shorter cellulose nanofiber was fabricated. The influence of enzymatic charge and hydrolysis time on cellulose fibers was analyzed by using scanning electron microscopy (SEM), Fourier Transform Infrared Spectrometer (FTIR), and X-ray diffractometer (XRD). SEM images revealed that the surface morphology change, effective diameter sharpening, and length shearing of cellulose fibers are as a result of cellulase hydrolysis. The XRD suggested that the cellulase acted on the amorphous regions more strongly than the crystalline domains during layer-by-layer hydrolysis. The enzymatic charge and hydrolysis time significantly affected the yields and hydrolysis products concentration. The enzymatic pretreatment assisted mechanical grinding could improve the uniformity of CNF and helped to obtain CNF with exact length according to the requirement for special applications.

scholarly journals Mechanical Properties and Cytotoxicity of Differently Structured Nanocellulose-hydroxyapatite Based Composites for Bone Regeneration Application

Nanomaterials ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 25 ◽  
Author(s):  
Vijay H. Ingole ◽  
Tomaž Vuherer ◽  
Uroš Maver ◽  
Aruna Vinchurkar ◽  
Anil V. Ghule ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Cellulose Nanofibrils ◽  
Bone Tissue Regeneration ◽  
Morphological Properties ◽  
Osteoblast Cells ◽  
Indentation Method ◽  
Composition Ratios ◽  
Ammonium Dihydrogen Orthophosphate ◽  
Dihydrogen Orthophosphate

The nanocomposites were prepared by synthesizing (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO)-oxidized cellulose nanofibrils (TCNFs) or cellulose nanocrystals (CNCs) with hydroxyapatite (HA) in varying composition ratios in situ. These nanocomposites were first obtained from eggshell-derived calcium and phosphate of ammonium dihydrogen orthophosphate as precursors at a stoichiometric Ca/P ratio of 1.67 with ultrasonication and compressed further by a uniaxial high-pressure technique. Different spectroscopic, microscopic, and thermogravimetric analyses were used to evaluate their structural, crystalline, and morphological properties, while their mechanical properties were assessed by an indentation method. The contents of TCNF and CNC were shown to render the formation of the HA crystallites and thus influenced strongly on the composite nanostructure and further on the mechanical properties. In this sense, the TCNF-based composites with relatively higher contents (30 and 40 wt %) of semicrystalline and flexible TCNFs resulted in smoother and more uniformly distributed HA particles with good interconnectivity, a hardness range of 550–640 MPa, a compression strength range of 110–180 MPa, an elastic modulus of ~5 GPa, and a fracture toughness value of ~6 MPa1/2 in the range of that of cortical bone. Furthermore, all the composites did not induce cytotoxicity to human bone-derived osteoblast cells but rather improved their viability, making them promising for bone tissue regeneration in load-bearing applications.

scholarly journals Application of xylanases from Amazon Forest fungal species in bleaching of eucalyptus kraft pulps

2007 ◽  
Vol 50 (2) ◽  
pp. 231-238 ◽  
Author(s):  
Roseli Garcia Medeiros ◽  
Francides Gomes da Silva Jr. ◽  
Sônia Nair Báo ◽  
Rogério Hanada ◽  
Edivaldo Ximenes Ferreira Filho
Keyword(s):  
Kraft Pulp ◽  
Morphological Changes ◽  
Dry Weight ◽  
Fungal Species ◽  
Amazon Forest ◽  
Kraft Pulps ◽  
Small Reduction ◽  
Bleached Pulp ◽  
Enzyme Pretreatment ◽  
Eucalyptus Kraft Pulp

Crude xylanase preparations from Penicillium corylophilum, Aspergillus niger and Trichoderma longibrachiatum were used to treat Eucalyptus kraft pulp, prior to chlorine dioxide and alkaline bleaching sequences. The enzyme pretreatment improved brightness and delignification of non-delignified and oxygen-bleached samples of eucalyptus kraft pulp. Xylanase preparations from T. longibrachiatum and P. corylophilum were more effective to reduce pulp kappa number. A small reduction in viscosity was obtained when the oxygen-bleached pulp was treated with xylanase preparation from A. niger. For all enzyme samples, the best release of chromophoric material from the pulp was at 237 nm. The enzyme preparation from P. corylophilum was responsible for the highest release of reducing sugar at a dosage interval of 10-20 IU/g dry weight pulp. Scanning electron microscopy studies of oxygen-bleached pulp after xylanase treatment revealed morphological changes, including holes, cracks, filament forming and peeling.

Properties of OQPaP Bleached Pulp of Pinus kesiya and Dendrocalamus giganteus Munro Made by Low-Temperature Kraft Pulping

2014 ◽  
Vol 900 ◽  
pp. 285-288
Author(s):  
Qi Xing Liu ◽  
Yang Chen ◽  
Jie He ◽  
Xin Gao
Keyword(s):  
Low Temperature ◽  
Kraft Pulp ◽  
Kraft Pulping ◽  
Paper Properties ◽  
Bleached Pulp ◽  
Pinus Kesiya ◽  
Lower Viscosity ◽  
Dendrocalamus Giganteus

In this paper, the low-temperature (the maximum pulping temperature was less than 150°C) and conventional (the maximum pulping temperature was 165°C) kraft pulp of pinus kesiya and Dendrocalamus giganteus Munro were bleached by OQPaP. Then bleaching properties and paper properties of two kinds of bleached pulp were compared and evaluated respectively. The results showed that the strength indexes of the kraft pulp at low temperature were significantly higher than those of conventional pulp with lower viscosity.

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